The 2000s are very similar to the 2200s, as built. Same motors, same control system, operable with all high performance series cars, etc. But because the 2000s were the first "high performance" cars built, there were some things which they tried and did not repeat on 2200s, 2400s, etc:
- Ceiling-mounted air-conditioning unit. Although it kept the cars cool, they were loud, and the two standee stanchions right under it also served as the AC unit's water outlet, a straight path to under the car. Sometimes these stanchions got plugged up. When they did, the train going around a curve would cause water would pour out from the AC unit and onto the passengers beneath it.
- Extensive use of aluminum paneling inside. Although preferable to regular steel, it's more prone to salt corrosion than stainless. There are only a few places on the 2000s where you can find stainless steel, the rest is aluminum. On the 2200s however, it's ALL stainless.
- No rehab. The 2000s were the last CTA cars to not get a mid-life rehab, along with the final 6000s. The 1-50s got theirs in 1985, the 2200s in 1989-1990, 2400s were done in house in the mid-to late-90s, 2600s in 1999-2000, and there's talk of a 3200 rehab happening soon. By the early 1990s the 2000 series cars were pretty worn out, and the CTA probably decided it would be best to simply replace the 2000s entirely with new 3200s rather than order a smaller number of new cars and put the 2000s through a rehab. In retrospect, that was probably a good decision.
You really have to compare a 2200 with a 2000 to see how much the former have been modified from their original state, and what it would take to take a 2000 and make it "current" with the rest of the fleet, even in the early 1990s. The 2200s originally had cushioned seats, backlit ads, different side paneling, conductor controls, and obviously no full-width cabs - and all of that has been changed. The four extant 2000s are actually the only high-performance "L" cars to be found anywhere that still have conductor stations, a feature that every car through the 2600s had when they were built.
That old car might be worth money!